Scaffolding



I. P. CRUSON Sept. 25, 1962 SCAFFOLDING 2 Sheets-Sheet 1 Filed Dec. 4, 1957 ZZARK Para Qaso v INVENTOR.

p 1962 I. P. CRUSON 3,055,464

SCAFFOLDING Filed Dec. 4, 1957 2 Sheets-Sheet 2 24-" 7.54 @asov INVENTOR United States Patent Office 3,055,464 Patented Sept. 25, 1962 3,055,464 SCAFFOLDING Izaak P. Cruson, Breslrens, Netherlands, assignor to N.V. Nederlands-Amerikaanse Fittiugtabriek, Deventer, Netherlands Filed Dec. 4, 1957, Ser. No. 700,633 Claims priority, application Netherlands, Dec. 13, 1956 Claims. (Cl. 189-36) The present invention relates to scaffolding and is concerned in particular with scaffolding constructed from tubular supporting members and tubular cross arm members as commonly obtained by securing one or more horizontal tubes to an upright support consisting of vertical tubes.

Scaffolding of this kind is now used extensively and the assembly of such scaffolding is mainly effected by securing horizontal tubes rigidly to vertical supporting tubes by applying auxiliary clamping means or gripping elements, which are positioned and then engage the respective tubes to be joined by means of bolts or locking wedges. However, the assembly and disassembly of such scaffolding require much time and labor and the use of special tools and moreover the usually specially cast clamping means fitted with bolts are rather expensive while the use of locking wedges in combination with gripping elements, which firstly have to be driven in, and later on have to be driven out, may also cause serious damage to the material of the connected tubes.

The primary object of the invention, therefore, is to provide scaffolding with simple and eflicient means for joining tubular cross arm members to tubular supporting members.

Another object of the invention is to provide securing means for assembly of scaffolding that consist of saddle portions, formed by collapsing and modelling the ends of the tubular cross arm members themselves. A further object is to provide a scaffolding comprising means for securing the saddle portions at the cros-arm members to the tubular supporting members.

Still another object is to provide a scaffolding that requires no special tools for assembly or disassembly.

Other objects and other novel features of construction and arrangements of parts will appear from the following description, wherein:

FIGURE 1 represents partly a top view of a steel scaffolding according to the invention;

FIGURE 2 represents a side elevation corresponding to FIGURE 1;

FIGURE 3 shows a horizontal cross-sectional view of a vertical tube and two horizontal tubes to a vertical tube secured thereto;

FIGURE 4 is represents in view, partially in cross section a specially preferred embodiment of a scaffolding connection;

FIGURE 5 represents a view of the connection according to the arrow in FIGURE 4, the axis of the vertical tube lying in the plane of the drawing;

FIGURE 6 represents a variant of a scaffolding connection, being chosen, however, a special form for the supporting surface of the bolt and the nut.

Referring more particularly to the drawing in FIG- URE 1 adjacent vertical tubes 1 and 2 constituting part of an upright support are connected with the end portions of horizontal tubes 3, 4 and 5 by means of bolts 6 and 7. The extremities of the horizontal tubes 8 and 9 perpendicularly disposed in relation to the tubes 3, 4 and 5 are connected correspondingly with the vertical tubes 1, 2. With every bolt 6 and 7 two horizontal tube end portions can be simultaneously connected to a vertical tube 1 tor 2.

As indicated in FIGURE 3, an example of ,a connection between the tube, is represented more in extension. It represents in particular the connection between the tubes 3, 4 and 1. The connection is such, that the axes of the horizontal tubes 3 and 4 lie in the same plane with the axis of the vertical tube 1. For that purpose the extremities 10 and 11 of the horizontal tubes 3 and 4 are flattened and bent in such a way that they may comprise a substantial part of the circumference of the vertical tube 1.

The ends 10 and 11 are further provided with holes 12 and 13 and the vertical tube 1 is provided with holes 14 and 15 of the same diameter as the holes 12 and '13. A bolt 6 reaches through these holes 12, 13, 14 and 15 connecting the tube ends 10 and 11 of the tubes 3 and 4 with the vertical tube 1, the axes of the holes 14 and 15 being horizontal. The volt 6 is provided with a head 16 and a nut .17, each provided with grips 18 and 19, causing the point of gravity of the head 16 and that of the nut 17 to fall outside of the centerline of the bolt 6. The tendency of the bolt and the nut to turn is hereby much restricted and loosening is thus avoided.

The bolt 6, which for instance may also be carried out as an eyebolt with eccentrically disposed eye is only threaded at its end 20. Between the head 16 and the beginning of the threaded part 20 is a smooth part 21, the diameter of which is substantially corresponding to the diameter of the holes 12, 13, 14 and 15 and the length of which at least matches the sum of the diameter of a vertical tube 1 and twice the thickness of a flattened end portion 10, 11 of a horizontal tube 3, 4. In this way no damage can be caused to the screw thread 20. The nut 17 is at its one side provided with an upright edge 22, the height of which is greater than the thickness of a flattened end 10, 1.1 and it is advantageous if, as indicated in FIGURE 3, the other side of the nut 17 is provided with a protective socket 23.

The inner diameter of the upright edge 22 is greater than the outer diameter of the threaded part 20. Hereby it is possible, if required, to clamp also one horizontal tube 3 or 4 instead of two on a vertical tube 1, 2 and still to see that never a tube end needs to rest on the threaded part of the bolt.

The connection of the tube 8 with the tube 1 and of the tube =9 with the tube 2 and various other connections are of the kind whereby only one horizontal tube is connected with a vertical tube.

On connecting the horizontal tube 8 with the vertical tube .1 the direction of the bolt used thereby is perpendicular to that of the bolt 6. The holes disposed to let pass this bolt and the bolt 6 are mutually spaced in the longitudinal direction of the tube 1, so that the tube 1 does not show too great a local weakening.

The particular fact, that in a scaffolding according to the invention, the axis of a horizontal tube is lying in the same plane as the axes of the vertical tubes, with which this horizontal tube is connected, gives this scaffolding construction a special advantage as it results into relatively small bending moments in the vertical tubes.

There is also a possibility of disposing inclined connecting bars, constituting a strut bracing. The fastening hereof to the substantially vertical tubes 1, 2 is effected in a way corresponding to that already described with relation to the horizontal bars 3 and 4.

As indicated in FIGURES 4 and 5 the collapsed end portions of two horizontal collinear tubes 3 and 4 of a scaffolding are secured to a vertical tube 1 by means of a bolt 28, which is inserted into the holes provided in the tubes 1, 3 and 4. Both ends of each of the horizontal tubes are identically shaped. The particular shape will be described with regard to the end of the tube 3, which is directed towards the tube 4. At these ends two adjacent saddle portions 24 and 25 are provided the axes of whichare directed substantially perpendicular one to the other. These saddle portions in the tube wall of the horizontal tubes can only be realised by making use of appropriate stamps and dies. The vertical tube 1 is partially embedded into the saddle portion 24, the undeformed part of the tube 4 being partly embraced by the saddle portion 25. The tube 4 is provided with similar saddle portions 24 and 25 corresponding to the saddle portions 26 and 27 for the tubes 1 and 3.

From FIGURE 4 it is obvious, that between the saddle portion 24 and the opposite wall part of the same tube some free distance in the form of a bag is provided, at that place the tube thus offering a considerable resistance against bending moments. Where the saddles 24 and 25 pass into each other the surface of the cross section of the tube 3 is greater than both the surface of a cross sec-- tion near to the neighbouring end of the tube and the surface of a cross section near to the securing bolt. The surface of the cross section of the tubes 3 and 4 in the place of the saddles 25 and 27 may gradually and advantageously increase to begin from the extremity of the tubes.

The saddles 25 and 27 will effectively counterset mutual articulating of the tubes 3 and 4 around the axis of the securing bolt or around the axis of tube 1, these saddles constituting planes of abutment at a considerable distance of the said axes.

The embodiment of the connection according to FIG- URE 6 shows the horizontal tubes 3 and 4, which by means of a bolt 28 and a nut with socket 2.9 are clamped to a vertical tube 1. In order to obtain a flat bearing surface for the head of the bolt respectively for the nut, there is formed a supporting surface 30 respectively 31 in the embedding part of the tubes 3 and 4 only around the hole through which the securing bolt is to be inserted. This fiat bearing surface provides also a less or more resilient support as may be desired in certain circumstances. The grips on the head of the bolt and on the nut are here replaced by eccentrically disposed eye cams. The eye cam 32 is on the head of the bolt 28 and the eye cam 33 is on the nut 29. This last mentioned embodiment excels by its smooth finishing of the bolt fastening, which is also of great value for the safety of the workmen.

While the invention has been disclosed in its preferred form, it is to be understood that the specific'ernbodr ment thereof as described and illustrated herein is not to be considered in a limited sense as 'there may be other forms or modifications of the invention which should also be construed to come within the scope of the appended claims.

What I claim is: l

1. An arrangement for connecting a first tubular member and two additional tubular members extending in axial alignment with each other at right angles to the first tubular member; said arrangement comprising flattened end portions on the adjacent ends of the additional tubular members which each include a seat part in the form of a section of a cylinder with the axis of the latter extending transversely with respect to the longitudinal axis of the related additional tubular member and with said seat part being completely disposed at one side of the longitudinal axis of said related additional tubular member, said seat parts seating against opposite sides of said first tubular member over circumferential extents of the latter each subtending an angle of approximately at least degrees, each of said seat parts having a central opening, said first tubular member having a pair of diametrically opposed holes registering with the central openings of said seat parts, a bolt extending through said registering central openings and said pair of holes, and a nut on said bolt securing both of said seat parts to the first tubular member.

2. An arrangement as in claim 1; wherein said bolt has a head with an eccentric handle extending therefrom and said nut has an eccentric handle extending therefrom so as to avoid loosening of the engagement of said nut and bolt by vibration.

3. An arrangement as in claim 1; wherein said seat parts each have a flat surface around said opening at the outside of the seat part so as to form a good support for the head of said bolt and for said nut.

4. An arrangement as in claim 1; wherein said seat part of each end portion is hollow and the latter further includes a hollow stop part extending from said seat part and being in the form of a section of a cylinder having its axis aligned with the longitudinal axis of the related additional tubular member, said stop part of each of the axially aligned additional tubular members engaging against the other of said axially aligned additional tubular members.

5. An arrangement as in claim 4; wherein each of said end portions further includes a hollow bag-like part forming a transition between said seat and stop parts to provide increased resistance to bending at said transition.

References Cited in the file of this patent UNITED STATES PATENTS 1,460,928 Tilden July 3, 1923 1,627,177 Henningsen May 3, 1927 1,645,980 Bearly Oct. 18, 1927 1,853,085 Scannell Apr. 12, 1932 2,308,831 Roney et al Jan. 19, 1943 2,619,390 Johnson Nov. 25, 1952 2,811,395 Jagiel Oct. 29, 1957 FOREIGN PATENTS 257,502 Switzerland Oct. 15, 1948 

